Facsimile refers to a telecommunications technology used to transfer copies of documents over a telephone network such as the publicly switched telephone network (PSTN) to a telephone number connected to a fax machine. Typically, an original document is scanned and the content of the document is converted into a bitmap image for the transmission. The fax machine at the receiving end of the transmission reconverts the bitmap image and prints a paper copy of the original document. Faxing provides a secure, traceable and non-repudiable mechanism for content delivery and can be particularly useful in business environments.
Faxing, however, has limitations. For example, conventional fax machines can only transmit black and white files with limited resolution in a specific format such as the Tagged Image File Format (TIFF). Further, the transmission speed can be very slow compared to today's Internet based standards. Not surprisingly, the faxing technology in recent years has faced increasing competition from Internet Protocol (IP) networks such as the Internet, local area networks (LANs), wide area networks (WANs), intranets, extranets, etc. These IP networks based alternatives may be referred to as Internet faxing. With Internet faxing, fax servers may be utilized instead of or in addition to standalone fax machines. A fax server generally refers to a server computer having the necessary fax software and hardware to receive and send faxes over IP and/or PSTN networks.
Using fax servers may reduce the cost of transmission since there is no telephone connection charge when sending a fax over the Internet. However, conventional faxing systems using fax servers do not confirm delivery of faxes. Furthermore, no mechanism currently exists to reduce the time a fax stays in a fax server, after the fax is sent from a sender and before the fax is received by a receiver.